slide-element
Promise-based library for animating elements with dynamic heights
... over. This library gets the job done using the Web Animations API, and it doesn't require elements to have fixed heights. Instead, element heights are calculated based on their contents, and then the appropriate values are applied to trigger a smooth, native transition. The animations themselves are powered by the same mechanics used within CSS transitions, making it one of the best ways to pull it off in terms of performance.